Valve mechanism for internal-combustion engines



R. RAGAN Oct. 22, 1929.

VALVE MECHANISM 4FOR INTERNAL COMBUSTION AENGINES Filed Aug. 5, 1924 3Sheets-Sheet ll l l Qwwntoz Malaya/w,

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w au M 6 e Oct. v22, 1929. R. RAGAN 1,732,911

VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Aug. 5, 1924 3Sheets-Sheet 2 3 Sheets-Sheet 3 0 www 6 R. RAGAN Filed Augg, 1924 VALVEMECHANISM FOR INTERNAL COMBUSTON` NGINES Oct. 22, 19.29.`

atlfozmg Patented Get. 22, i929 illlE STATES ATENT OFFICE RALPH RAGAN,0F ATLANTA, GEORGIA Application filed August 5, 1924. Serial No.730,317.

llhis invention is an improvement in valve mechanisms, ot theoscillating type, and one ot then principal objects ther-eet is tomaterially increase the etiiciency ot the motor, by arranging the inletand exhaust ports tor each cylinder, and the single ported valve whichcontrols them, substantially in alignment with the axis of the cylinder,so `that on the suction stroke no retardation ot the combustible mixturewill be experienced by appreciable changes in direction oi the incom inggases or obstruction ot its passage, and, on the other hand, on theexhaust stroke, thorough scavengin,5wT et the cylinder will be attainediler the like reason that no material change in direction, and noobstruction ot the path, ot the exploded gases will be necessitated.

Another object of the invention is to improve the etliciency of themotor by utilizing` the valve bore or chamber as the combustion chamberot the cylinder, and by allowing the use of inlet and exhaust ports etmuch larger area than ordinarily, and 'further by so shaping the valvethat the rate el' combustion ot the compressed gases, on the workingstrolre, is increased.

t further object et the invention is to provide an oscillatino valve inwhich the presupon the valve, tending to seat and to unseat it areequalized, so that the work required to operate the valve remainsconstantly the same, irrespective oi the load on the motor so iar as thepressure is concerned, so that no more power will be required, asconcerns the pressures, to actuate the alve when the engine is underheavy load, than when it is running idle.

A further object of the invention is to provide an oscillating1 valvestructure in which the wear between the valve parts and their seats isautomatically taken up, and in which the expansion and contraction etthe parts due toA temperature changes is automatically compensated for.

A further object ot the invention is to provide an improved means foractuating` the valve.

lVith these and other objects in view, which will become more apparentas the description proceeds, the invention resides in the construction,combination and arrangen'ient of parts, hereinafter more fully describedand clain'ied, and illustrated in the accompanying drawings, in whichlike characters of reference indicate like parts throughout the severalligures, and in which Fig. 1 represents a vertical transverse sectionalview taken through one cylinder et a multiple cylinder engine equippedwith valves and associated parts, constructed according to my invention.

Fig. 2 represents a sectional view at right angles to Fig. l, taken onthe line 2 2 thereof.

Fig. 3 represents a horizontal sectional view on the line 3 3 et Fig. l.

Fig. l represents a view taken on the :line L -lc of Fig. l showing` aportion ot the upper face of the cylinder block, the valve beingremoved, and illust-rating the contiguration of the valve seat.

Fig. 5 :epresents a plan view oi the upper halt of the valve. l

Referring` more particularly to the drawing the cylinder block ot' theengine, which may be of the usual four-cycle type usually used inautomobiles, is indicated at 5, the cylinder walls being indicated at 6,and at 7 is indicated the space tor the water circulation around thecylinders, as is usual.

The cylinder head of the engine, which is likewise provided with watercirculation spaces 7', is indicated generally at 8, such head beineremovably secured to the block by means oit studs 9.

On one side ot the cylinder bleek is an integral supportingl shelt orbase 10 en which the bearings 1l tor the cam shaft l2 are mounted. Thecylinder head has a lateral extension 13, which together with the shelf,over which it is located, forms a housing for the cam shaft and theassociated mechanism for operating the valves. The shelf or base 10, isin eflect a widened portion of a flange 14, which encircles. thecylinder block in a horizontal plane, and upon which the cylinder headrests throughout its lower perimeter. Thus the cylinder head, acts as acomplete housing for the valves, to be hereinafter described, and thevalve operating mechanism, it being understood that a tight joint ismaintained between the cylinder head and the flange, so that the oil forlubricating the various parts, as. will become more apparenthereinafter, will be maintained against escape. Further this structureis advantageous in that when the cylinder head is removed the valves,cam shaft, and associated parts are fully exposed and accessible forremoval, adjustmentor repair. Hard metallic spacing washers il,surrounding the studs 9, or equivalent means, are used to accuratelyspace the cylinder head with respect to the cylinder block, acompressible gasket 3 being positioned between these parts as is usual.

The inletport 15, and the exhaust port 16 lfor each cylinder, is formedin the cylinder head above the cylinder, and intermediate these ports isprovided a threaded opening 17 for the reception of the spark plug 18.

Above the cylinder head on opposite sides of the medial line of themotor are arranged the intake and exhaust manifolds 19 and 20,'

respectively, as clearly indicated in F 1.

The inner ends of the inlet and exhaust ports 15 and 16 are arrangedsubstantially close together, and these ports depart only at a smallangle with the axis of the cylinder.

The valve, indicated generally at 21, is interposed between the cylinderhead and the cylinder block in 'alignment with the cylinder, and henceit will be observed from this structure, that the combustible gases enthe intake stroke, and the burned gases on the exhaust stroke, have aclear and free passage, without material change in direction, into andout of the cylinder, hence tending towards an increased eliiciency ofthe motor by reason of the drawing of a full charge on the intake strokeand a complete scavenging of the cylinder on the exhaust stroke. This byreason of the fact that the paths traversed by the incoming and theoutgoing gases are substantially in alignment with the axis of thecylinf der, are free of any material changes in direction, and areperfectly unobstructed.

The single oscillating valve, for each cylinder, which controls theinlet and the exhaust port thereof, includes a lower half 22, and anupper half 23. The lower half has a bearing seat 26 in the cylinderblock immediately above the cylinder, and centered with respect to theaxis thereof, and the upper half has a similarly situated bearing seatin the lower side of the cylinder head. The lower half of the valve hasa cylindrical body portion 24, and a base or bearing portion 25 which atany horizontal section is rectangular in outline. In vertical sectiontransversely of the cylinder block the bearing 25 is semicircular inshape, being struck from the point 0, about which the valve oscillates,and the valve seat 26 in the cylinder block, similarly struck from thepoint O, receives the bearing 25 at the lower end of the valve. It willbe observed that the shoulders 27 at the ends, longitudinally of thecylinder block, of the valve seat 26, confines the valve to a pureoscillatory movement, and prevents any twisting of the valve in itsseat.

Longitudinally of the motor the cylindrical portion 24 of the lower halfof the valve is provided with diametrically opposed lugs 23 which areengaged by the bearings Q9 of a yoke 30, actuated, as will behereinafter described, froin the cam shaft, for oscillating the valve.

The upper half 23 of the valve has a cylindrical portion 31, which isslidably received in the cylindrical portion Q4 of the lower valve half,and is provided with rings 32 for maintaining a gas tight joint betweenthe valve halves.

T he valve, as shown is provided with a bore or chamber extendingtherethrough which forms the combustion chamber for the cylinder and thearea of the cylindrical opening in the lower portion of the upper valvehalf, is equal to the area of the opening 33 in the head of thecylinder, and likewise is equal to the area of the opening or port 3l atthe upper end of the valve half. As indicated in Fig. 5 the opening orport at the upper end of the valve is oblong in shape, being longerlongitudinally of the cylinder block than transversely thereof, and thisopening correspoiuls in area with the opening of each of the inlet andexhaust ports 15 and 1G, respectively. Further the area of the ports ismuch larger than that used in ordinary construction.

Transversely of the valve the inner walls 35 of the upper valve halfiiare inwardly and upwardly toward the valve opening 34, from thecylindrical opening in the center of the valve, and the walls .36longitudinally of the, valve flare upwardly and outwardly to the valveopening- 34 from the cylindrical opening at the center of the valve. Thea ngles at which the walls 35 and 3G are disposed, and the areas ofthese respective walls, are so designed that the pressures which, actingupon the walls 36 tend to unseat the upper hal l of the valve, andacting upon the walls 35 tend to seat the upper end of the valve, areequalized, so that irrespective of whether the engine, is idle, orwhether it is under load, the power necessary to operate the valveremains constant in so far as the pressure is concerned.

It will be noted that the combustion chainber is substantially in theshape of a cylinder situated centrally over the piston, and of a smallercross-sectional area than the cylinder proper, and that the upperportion -of this combustion chamber flares outwardly on opposite sidesand inwardly on the other two sides. The result of this construction isthat on ignition, eddies and disturbances in the propagation ofcombustion takes place so that maximum combustion of the compressedgases is effected. Further the velocity of combustion is materiallyincreased over that in the ordinary construction, wherein the diameterof the combustion chamber equals or is greater than the diameter of thecylinder. rlhis rapidity of combustion effects a much quicker' action onthe head of the piston. Further the direction of combustion iscentralized and immediately over the piston. It is also to be observedthat the exhaust gases in passing through the valve raise thetemperature of the body portion thereof to a high degree. The parts ofthe valve in contact with and adjacent to the valve bearings, however,are kept suciently cool by reason of the water-cooled valve seats. Thishigh heating of the body portion of the valve is advantageous in that onthe intake stroke the gases are raised in temperature and are morehighly volatilized, so that at the end of the compression stroke thecharge is in a highly heated state. Moreover, the incoming gases intaking heat from the valve body keeps the temperature thereof withinsafe limits.

llhe locationof the spark plug opening or pocket adjacent to the inletport, effects a cleaning or clearing action of the pocket by reason ofthe fact that on the beginning of opening of the inlet port, theinrushing gases in attempting to occupy the partial vacuum rush andswirl through this pocket and carry away any deposits which may havebeen left therein at the end of the exhaust stroke.

From Fig. l it will be observed that the bearing 87 for the upper halfof the valve is struck with a greater radius and from the same centerthat the bearing and seat for the lower valve half are struck, and thatthe set 38 for the upper valve half, on the under-face of the cylinderhead, is similarly struck from the same center, and with a radius equalto the radius of the upper valve bearing. The bearing of the upper valvehalf is extended transversely of the engine to provide the skirts 39 forclosing both the inlet and exhaust ports when thevalve is in compressionand firing position. The extent of the skirts is such that when thevalve is in intake position the exhaust port is closed, and on the otherhand when the valve is in exhaust position the intake port is closed.rlhe skirts are reinforced by integral webs which connect them with thebody portion of the upper valve half. i

The sliding contact between the upper and lower valve halves and theclearance 2 between them allows relative movement .of these portions tocompensate for expansion and contraction due to temperature changes, andalso allows for the valve halves to constantly 'follow their seats aswear takes place, and

lower valve halves against their seats, and

automatically takes up any wear which may occur between the valve halvesand their seats, and also maintains a sealed contact between the movingvalve bearings and their seats.

The metal of the upper valve seat 38, located between the inlet andexhaust ports 15 and 16 respectively, and. corresponding in ar'ea to thevalve port 34, is cut away slightly as at 43, so that no replacement ofoil on this portion will be necessary. Otherwise, when the valve is infiring position the oil on the portion of the seat exposed through thevalve port would be constantly burned away and hence require constantreplenishment. Further, due to this construction, no part of the seat,against which the upper valve bearing moves, will be subjected tocorrosion or carbon deposits, it being observed that the cut awayportion 43 is of sufficient depth that pitting or corrosion, or carbondeposits on it, can take place to great extent, without danger of thevalve bearing coming in contact therewith in the oscillating movementsof the valve. rlhe cut away portion also reduces the surface contact ofthe valve and hence reduces friction. It is against this portion of thecylinder head that the force of the explosion comes.

Each of the yokes 30, for operating the engine valves, heretoforereferred to, at the outer end of its arm 44,`is pivoted as at 45 to aslide, indicated generally at 46, which slide is reciprocated throughthe operation of the cam shaft, for oscillating the valve. The slideincludes a base portion 47 on which uprights 48 and 49, on oppositesides of the cam shaft, are carried, the uprights being connectedtogether at their upper ends as at 50 and 51 respectively. The uprights48 are provided with the straps 52 which at their adjacent ends areprovided with ears or lugs 53 between which the outer end of the yokearm 44 is pivoted by the pin 45. The uprights 48 are provided withaligned bosses 54 in which a shaft 55 is carried. On this shaft inalignment transversely with the axis of the valve is a cam follower inthe form of a roller 56. This roller cooperates with a cam 57, carriedby the cam shaft 12, Vfor moving the valve in one direction. A shaft 58is similarly carried in the uprights 49 on the opposite sides of the camshaft, and on this shaft 58 are mounted a.l pair of cam followers 59intheform of rollers. These followers cooperate with reversed curve cams60, which flank the cam 57, for actuating the valve in the oppositedirection.

The configurations of the cams 57 `and 60 yare such that when the valvehas moved to compression position it remains stationary during thecompression and firing strokes. The cams are lso cut and positioned onthe shaft, that the portions of the cam or cams which vrnove the valvein one direction are set opposite the portions of the cam or cams whichmove the valve in the opposite direction, the rollers, during thecompression and working strokes riding on the portions of the camsurfaces which are concentric with the cam shaft, hence keepingrthevalve stationary during these strokes.

i Between the straps 50 and 51, which connect the respective uprights 48and 49 at their upper ends, is mounted an adjustingstud 6l, such studpassing through bosses carried 'on the straps, and a sleeve or sleevesG2 encircles this stud and is clamped between the Vbosses -on the straps50 and 5l. To take upwear between the cams and the followers Y. rllheslide reciprocates on the guide bars 63, which pass through bearings 64mounted in bosses onthe base 47 of the slide, and are threaded intobosses on the cylinder block as at 65. The outer ends ofthe bars or rods63 are supported kby the centering pins G5y carried in the side wallofthe cylinder head and equipped with lock nuts 66.

Freni the foregoing it will be observed thatthe slides areconlinedtoreciprocating motion transversely of the engine and that theaction of the camsin oscillating the valves -is positive in bothdirections, there being no play between the camsand their followers.This insures of a silent operation of the valves, as well as a positiveoperation of them in' both'directions. Furthermore by the use of acentral and a pair of flanking cams, together with the central and thespaced cam followers, the thrust in bot-h directions is in the samestraight line transversely of the motor, and any tendency of the slideto cock in one direction or the other is eliminated.

For lubricating the cam shaft and its associated parts, oil underpressure may be introduced through the line leading through the camshaft bearings, indicated generally Y at G7. rlhis line communicatingwith a bore 68 in the cam shaft, and thence through ducts 69 to thesurface of the cams, being thrown olf and sprayed in all directions bythe centrifugal action due to the rotation of the cam shaft, as well asto the pressure supplied by an oil pump (not shown). The interior of thehousing, will thus of course be con stantly filled with the oil spray,and oil will collect in the oil channel 68 (see Fig. 2) which isprovided longitudinally of the cylinder block at the top thereof. Thelower portions of the valves, being in alignment with this oil channel,will thus be constantly bathed in oil. The supply of oil being constant,the channel of course will overflow, the excess oil finding its way backto the oil sump to be recirculated in the usual way, so that the supplyofK oil for the lower valve bearings is in circulation.

Due to the constant particles of oil sprayed and thrown off by themoving parts, the bearing surface of the upper valve skirt, on the sidetoward the cam shaft, and to some extent on the opposite side also, iskept bathed in oil during the oscillation of the valve.

For additionally insuring a supply of oil to the side of the upper valvebearing, away from the cam shaft, a pressure line, indicated generallyat 70 connects as at 7l with an oil line 72 on the inside of thecylinder head and running longitudinally thereof and near the valves. Asthe valve skirts on the side adjacent the oil line 72 reciprocates pastthis oil line, oil under pressure passing through ducts 73 in the oilline spray upon this side of the valve bearings. It will be noted thatthe position in the oil line 72 is such that the skirts of the valves inmoving to intake position pass into alignment with the ducts 73 andhence receive the oil spray on their bearing faces. In moving away fromthe intake position, the skirts move upwardly beyond the ducts 73, andthe oil issuing therefrom is sprayed towards the lower valve bearings,acting as an additional source of oil supply for these bearings.

I have found that an engine constructed according to my invention iscapable of being operated at high compression pressures, and at the sametime is free from danger of detonation, and hence the power andeflieiency of the engine is very high.

The foregoing description has been given for purposes of illustrationonly, and no limitations should be deduced therefrom, but the appendedclaims should be construed as broadly as possible in view of the priorart. And I do not intend to be limited by the use of the valve andoperating mechanism in the particular engine shown, but intend to'applyit to all engines susceptible of the advantages of its use.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is,-

l. In an internal combustion engine, op-

posed arcuate valve seats having a single center of curvature and havingradii ot ditiierent lengths, one of said seats having a single portcommunicating with the cylinder and the other having two spaced ports,and a valve oscillating around the single center of curvature of the twovalve `seats and hav ing opposed bearings resting against said seats,said valve having a bore in constant registration with the single portand adapted to be placed in registration with either of the spaced portsor to be closed by the 1naterial therebetween.

2. In an internal combustion engine, the combination of a cylinderhaving a single port, a removable cylinder head provided with intake andexhaust ports in substantial alignment with the cylinder port, opposedarcuate bearing seats in the cylinder and cylinder head struck withdifferent radii from a single center, and a valve oscillating around thecenter of curvaturel of the valve seats and having opposed bearingsseating against said seats, said valve being provided with a bore inconstant registration with the cylinder port and adapted to be placed inregistration with either the intake or exhaust ports or to be closed bythe material therebetween, and means for oscillating the valve.

3. In an internal combustion engine, the combination of acylinder havinga single port, a cylinder head provided with intake and exhaust ports insubstantial alignment with the axis of the cylinder, an oscillatingvalve having a bore in constant registration with the cylinder port andadapted to be placed in registration with either the intake or exhaustports, said valve being interposed between and bearing against thecylinder and its head and having a center ot oscillation unequidistantfrom itsJends and means tor oscillating the valve.

ll. In an internal combustion engine, the combination of a cylinderhaving a single port, a cylinder head provided with intake and exhaustports, an oscillating valve having a bore in constant registration withthe cylinder port and j forming the combustion chamber of the cylinderand adapted to be placed in registration with either the intake orexhaust ports, said valve having upper and lower sections movable withrespect to cach other interposed between and bearing against thecylinder and the cylinder head and having a center of oscillationuneqnidistant from its ends and means 'for oscillating the valve.

5. In an internal combustion engine, the combination ol a cylinder', acylinder head, there being a space between the cylinder and cylinderhead subject to oil spray, an oscillating valve interposed between andbearing against the cylinderl and cylinder head and having upper andlower sections movable with respect to each other, and `resilient meanson the outside of the valve and subject to the temperature of said spaceand tending to separate the valve sections.

6. In an internal combustion engine, the combination of a cylinder, acylinder head, an oscillating valve having seats of dillerent radii ot'curvature and having upper and lower sections movable with respect toeach other and provided with a bore forming the combustion chamberoiithe cylinder, interposed between and bearing against the cylinder andcylinder head, and means tor operating the valve.

7. In an internal combustion engine, the combination of a Cylinder, acylinder head, there being a space between the cylinder and cylinderhead subject to oil spray, an oscillating valve interposed between thecylinder and cylinder head and having' sections movable with respect toeach other, and a ring like spring means on the outside ot the valve andsubject to the temperature of said space interposed between the sectionsand tending to separate them.

8. In an internal combustion engine, opposed arcuate valve seats, one ofwhich has a singleport and the other of which has two ports, and a valveinterposed between the seats and having a center of oscillation un.-equidistant from such seats, said valve having a bore one end of whichis in constant communication with the single port in one valve seat, andthe other end of which is formed into an elongated port adapted to beplaced alternately in communication with each o'll the two ports in theother valve seat.

9. In an internal combustion engine, a cylinder having an arcuate valveseat in the end thereof provided with a single port, a cylinder headhaving an opposed arcuate valve seat provided with two ports, anignition device in the' cylinder head between the two ports, and anoscillating valve interposed between the seats and having a bore one endof which is in constant communication with the single port and the otherend of which is adapted to be placed alternately in communication witheither of the two ports, such bore when in intermediate position beingin registration with the ignition device.

l0. In an internal combustion engine, a cylinder having a port, acylinder' head having a plurality of ports, an oscillating valveinterposed between the cylinder and cylinder head and having a bore inconstant communication with the port in the cylinder and adapted to beplaced in registration with eitherI of the plurality of ports in thecylinder head, and an ignition device with which the bore is inregistration when out of registration with either of the plurality ofports in the cylinder head.

11. In an internal combustion engine, a cylinder, an oscillating valvehaving a bore centralized. with respect to the cylinder and of smallercross sectional area than said cylin- Y der, said bore constantlycommunicating with the cylinder, inlet and outlet ports in communicationwith which the bore of the valveis adapted to be alternately placed, and

an ignition device from which communication to the cylinder isestablished only by the bore of the valve.

12. In an internal combustion engine, a cylinder, a valve forestablishing both intake and exhaust means for the cylinder, said tionalarea than said cylinder, means for igniting the charge in the cylinderthrough the bore of the valve, said bore adjacent the ignition meansbeing of different cross sectional configuration than the remainder ofthe bore.

14. In an internal combustion engine, a cylinder head having an arcuatevalve seat provided-with spaced ports, an oscillating valve having abearing seated against said seat and Y provided with a port adapted tobe alternately placed'in communication with said spacedY ports, thevalve 'seat between the' spaced ports, corresponding in areasubstantially with the area of the valve port being cut away.

15. In an internal combustion engine, opposed arcuate valve seats ofdifferent radii of curvature, a valve interposed between the seats andoscillating around the center of curvature thereof, a slide confined toa recipfrocating movement, articulated connecting means between theslide and the valve at a point offset from the center of oscillation ofthe valve, and cam means for positively mov- Aing the slide in bothdirections.

16. In an internal combustion engine, opposed arcuatevalve seats, avalve interposed between the seats and oscillating around the center ofcurvature thereof, a slide conlined to a reciprocating movement, a yokeoperated by the slide and pivotally connected to the valve at a pointoffset from the center of oscillation of the valve, vcam means forpositively vmoving `the slide in both direct-ions, and

to the cam means. Y

17.-In`an internal combustion engine, opposed water-cooled arcuate valveseats, an oscillating valve having bearing surfaces in means foradjusting the slide with respect constant `contact with'said seats andcooled thereby, said valve having a body portion uncooled save byconduction, said valve providing both the exhaust and intake means forthe engine cylinder, whereby the body portion of the valve will behighly heated by the exhaust gases, and the incoming gases will beheated in turn by said valve body.

18. In an internal combustion engine, opposed valve seats cooled by acirculating medium, an oscillating valve having sections movable withrespect to each other and bearing at its ends against said valve seatsand being cooled at its ends thereby, said valve having a body portionuncooled save by conduction, said valve providing both the exhaust andintake means for the engine cylinder, whereby the body portion of thevalve will be highly heated by the exhaust gases, and the incoming gaseswill be in turn heated by said valve body.

19. An oscillating valve for internal combustion engines comprising aplurality of parts slidable with respect to each other one of such partshaving outwardly fiared walls, packing means maintaining a gas-tightjoint between the valve parts, and a resilient ring surrounding one ofthe parts and bearing against the flared walls thereof and abutting anend of the other part.

20. In an internal combustion engine, opposed valve seats in thecylinder and cylinder head, an oscillating valve interposed between andbearing against said seats. the interior of the valve having surfacesinclined in opposite directions and so proportioned that pressurestending to unseat the valve in either direction are counterbalanced bypressures tending to seat the valve in that direction.

21. In an internal combustion engine, opposed valve seats, a valveinterposed between the seats and subjected to the compression developedin the engine cylinder, said valve being provided with surfacessubjected to the pressure and tending to seat the valve in onedirect-ion, said valve having other surfaces subjected to the pressureand tending to seat the valve in a like degree in an opposite direction.

22. In an internal combustion engine, the combination with a cylinderand piston, ot a valve casing having intake and exhaust ports and a portopen to said cylinder, a valve mounted for oscillation in said casingand having a passage therethrough forming a part of the combustion spaceof' the cylinder, said passage being connected continuously to saidcylinder port, during intake, compression, power and exhaust strokes olsaid piston.

23. In an internal combustion engine, the combination with a cylinder ofa communicating valve casing having intake, ignition, and exhaust ports,of an oscillatable valve journaled in said casing and provided with asingle passage for establishing communication successively between theintake port and cylinder, the ignition port and cylindei1 and theCylinder' and exhaust port.

24. In an internal combustion engine, the combination With a Cylindei1of a communi eating valve easing having intake, ignition, and exhaustports, of an osoillatable valve joui'naled in said casing and providedWith a single passage for establishing communication successivelybetween the intake port and cylinder, the ignition port and cylinder`and the cylinder and exhaust port, said passage in said valve beingshaped to conform to onehalf oithe length of a venturi.

In testimony whereof I hereunto aiiix my sign ature.

RALPH RAGAN.

